connection to the two turbines is a 33.5-foot diameter tunnel. At full flow of 19,800 cubic feet per second, the velocity of water in the tunnel will be about 22.5 feet per second. The total rated capacity of the two equal units is 140 megawatts. The hydroelectric plant at Jocassee Dam has an inlet at 1043 feet above mean sea level. The connections to the four turbines consist of two 33.5-foot-diameter tunnels. At full total flow of about 29,000 cubic feet per second the velocity of water in the tunnels will be about 16.5 feet per second. The total rated capacity of the four equal turbines is 610 megawatts. These four turbines at Jocassee are reversible and can be used to pump water back into Lake Jocassee at times of low power demand. Under this latter condition the total flow will be 26,000 cubic feet per second and the velocity in the tunnels will be 14.7 feet per second. The Keowee Dam hydroelectric plant will be operated with a plant factor of about 5% (normally one or two hours each weekday). The stream bed of Hartwell Reservoir just below Keowee Dam is at 655 feet above mean sea level, i.e., 5 feet deep at the Keowee Dam, but during operation of the Keowee Dam hydroelectric station, the levels in the receiving stream will rise substantially. These levels are (for normal lake levels). Distance from Keowee Dam (feet) 2400 9800 23000 Hartwell Headwater Level at Full 661.4 The Jocassee Dam hydroelectric station will be operated with a plant factor of about 14%. The lake bed level of Keowee at the Jocassee Dam is about 735 feet above mean sea level. This gives a normal depth of 65 feet at this point. As a result, the effects of operating the Jocassee hydrostation and the water level in the discharge area will be less noticeable than at Keowee dam. The lake levels will fluctuate due to the operation of the hydroelectric stations. Limits on this fluctuation are set at 3 feet for Keowee and 6 feet for Jocassee, over an unspecified period. This range allows for flexibility of operation of the hydroelectric stations. Operation of the Jocassee hydroelectric station for 10 hours continuously, without a corresponding operation of the Keowee plant, would result in raising the level of Lake Keowee about 1.3 feet, and dropping the level of Lake Jocassee about 2.5 feet. This Any steam-electric generating plant must discharge into the environment a large fraction of the heat that is produced by burning or fissioning fuel. Each unit of the Station when at full power must dissipate about 1650 of the 2568 megawatts of heat being produced. discharge of heat cannot be avoided or, for present-day power reactors, significantly reduced. The waste heat at the Station is transferred into the waters of Lake Keowee. (In fact, the potential for doing this was the primary reason for the choice of the site and the creation of the lake.) b. Water Flow The relationship of the lake and the condenser cooling water intake and discharge is shown in Fig. III-5, which also shows typical lake surface temperatures expected, with the addition of thermal discharges from the Station. (3) Water is taken from the Little River arm of the lake and discharged just above the dam on the Keowee River arm. It is nearly 2 miles by lake from the point of discharge to the mouth of the intake canal. More details of the intake are shown in Fig. III-6. A natural cove was deepened and extended to within a few hundred feet of the power plant. Across the mouth of the cove a skimmer wall was constructed extending from above the surface of the lake (normally 800 feet above mean sea level) down to an elevation of 735 feet. This wall insures that cooler water from near the bottom of the lake, enters the intake canal. The water velocity under the skimmer wall will be about 0.6 feet per second at full flow. Further into the intake cove is a submerged dam, or weir, with its crest at 770 feet above mean sea level. This will retain enough water in the intake canal to provide ample condenser cooling for an orderly shutdown of the plant in the event that one of the Lake Keowee dams or dikes fails and the lake drains. (From the weir to the intake structure is nearly 3/4 mile.) The excavated portion of the intake canal is 100 feet at its bottom (elevation 760 feet). When the lake is full (surface elevation 800 feet) the maximum flow through the three condensers (see Fig. III-7) will produce a water velocity in the canal of less than 1 foot per second. At the most extreme drawdown that will be allowed (to 775 feet), the velocity in the intake canal would reach about 3.5 feet per second, but at the screens, the velocity would still be less than 1 foot per second. The intake screens are stationary, of galvanized iron mesh with 3/8-inch openings. The intake structure is shown in Fig. III-8. Each unit has its own condenser, supplied with water by means of four pumps, each delivering 177,000 gallons per minute (about 394 cubic feet per |